Specifictity Non-reducing terminal Beta-(1-4)-galactose. Number of antennae does not affect cleavage rate. Fucose linked to the penultimate N-acetylglucosamine will block cleavage of the galactose.

Specific Activity One unit of Beta-(1-4)-galactosidase is defined as the amount of enzyme required to produce 1 µmole of p-nitrophenol (pNP) in 1 minute at 37˚C pH 5 from p-nitrophenyl-beta-D-galactopyranoside.